Silver halide color photographic light-sensitive materials are first subjected to image-wise exposure and then to development in an aromatic amine color developing agent to form a color image through the reaction of developing agent oxides that are produced as a result of this process and the color image forming couplers (referred to below as "couplers"). Normally, a combination of a yellow coupler, a cyan coupler and a magenta coupler is used in color photographic light-sensitive materials.
Pyrazolone couplers, pyrazolobenzimidazole couplers, indazolone couplers and pyrazoloazole couplers containing pyrazolotriazoles are known as magenta couplers. Further, 4-equivalent couplers are known which, because of equivalent properties with respect to silver, theoretically require 4 moles of silver halide in order to form 1 mole of dye, and 2-equivalent couplers are known which require 2 moles of silver halide.
2-equivalent couplers, which have a lower consumption of silver halide required for development, are advantageous for practical purposes and are the subject of considerable research and development work.
However, when one considers the preservation of photographic records, which is the basic purpose of color photographs, one finds that the image retention characteristics are not yet satisfactory and the light-fastness of the magenta color image in particular is much poorer than that of the yellow and the cyan color images. Therefore, magenta color couplers have been the object of much research and many proposals for their improvement have been set forth. Further, with regard to the fastness of images as affected by heat and humidity, there have been improvements in the fastness of cyan images and there are also increasingly strong demands for the improved fastness of magenta images.
Moreover, in view of the customers' demands and for the sake of protecting the environment, there have recently been strong calls for guaranteeing a satisfactory color density and image retention even when conducting the so-called rapid processing in which the development time is short, conducting development processing which involves essentially no benzyl alcohol, conducting a washing treatment using little or no water, and conducting processing in which there are, considerable changes in the ratios of the components contained therein and in the amounts of the components occurring during operating conditions.
2-equivalent 5-pyrazolone type magenta couplers are not well suited for practical purposes since they are also difficult to synthesize, the stability of the couplers per se is poor, and they display many side effects when used in photographic materials.
The present inventors having conducted intensive studies on arylthio elimination type 5-pyrazolone magenta couplers which are easy to synthesize, and they have recently developed 2-alkoxyphenylthio elimination type 5-pyrazolone magenta couplers which have been proposed in U.S. Pat. No. 4,413,054 and 4,351,897 and JP-A-60-57839, etc (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). However, when the color developing solution contains large amounts of polyvalent cations having a valence of 2 or more, especially calcium ions, these arylthio elimination type 5-pyrazolone magenta couplers cause a reduction of the color density and desensitization results. Addition of the compounds proposed in JP-A-59-157632 in order to prevent this results in the deterioration of the image retention characteristics and staining in conditions of exposure to light, heat or humidity. Also, there is the drawback that yellow stain occurs in the white background of unexposed portions of the photographic material. Also, the method proposed in JP-A-60-159850 is undesirable for practical purposes since manufacturing costs are high with this method.
Moreover, these arylthio elimination type 5-pyrazolone magenta couplers have the further drawback that unexposed portions of the photographic material turn a magenta color with the lapse of time following development processing.